1. Technical Field
Embodiments of the present disclosure relate to network address translation, and more particularly to a network address translation device and packet processing method.
2. Description of Related Art
Session initiation protocol (SIP) acts as a foundation protocol of voice over Internet protocol (VoIP) technology. Many IP telephones or soft phones communicate with each other by SIP. Generally, in such communication, two IP telephones act as two SIP clients and communicate with each other and the two SIP clients send packets including source addresses and destination addresses to each other. A network address translator (NAT) is a necessary part for a local area network (LAN) to transmit the packets to a wide area network (WAN). The NAT needs to translate the addresses of the packets if the two SIP clients are disposed on different sides of the NAT.
However, sometimes the SIP clients will transmit a plurality of anomalistic packets. The NAT will not translate the anomalistic packets and will directly drop the anomalistic packets, which reduces voice definition or even disables communication between the SIP clients. Therefore, a heretofore unaddressed need exists for a NAT that can overcome the limitations described.